<html>
<head>
<style>
#box * {
    -webkit-flow-into: flow;
}

#box {
    -webkit-flow-from: flow;
}

.child {
    width: 40px;
    height: 40px;
    border: 1px solid red;
}

.grand-child {
    width: 20px;
    height: 20px;
    border: 1px solid lime;
}
</style>
</head>
<body>
    
    <div id="box">
        <div id="e1" class="child"></div>
        <div id="e1" class="child">
            <div class="grand-child"></div>
        </div>
        <div id="e1" class="child"></div>
    </div>

    <div id="other-box"></div>
</body>

</html>
